The speed of movement in the 21st century has increased greatly, and the rhythm of life and requirements for mobility have reached levels that were undreamed of just a couple of generations ago. In such conditions, the path from point “A” to point “B” along the shortest and, preferably, comfortable route is both an ideal and a norm. However, roads for Russia and their condition are a sore subject. We are not even talking about the quality of the road surface; it is still better to ask such questions directly to the builders, but about the connectivity and density of the road network.
On a city scale, the level of development of the road network, as well as existing natural and man-made barriers, often force the route to be increased, both in terms of travel time and its length. A clear example is the connections of radial urban directions - when the distance to the required object “in a straight line” is hundreds of meters, and in order to reach it along the existing road network it is necessary to overcome more than one kilometer of roads.
This is more than just an inconvenience: annually, losses due to poor condition and insufficient roads amount to 3% of the country's GDP. Imagine, even in the USA, where the density of roads is many times higher, the deficit of bridge structures is 32% (and this is with a total number of bridges of all types being 574,671). What can we say about Russia?
A solution to this problem could be bridges made of aluminum structures, but so far the pace of their construction leaves much to be desired. With all their advantages, the first two such bridges in modern Russia were installed in the Nizhny Novgorod region this summer. It’s worth noting right away that for now we are talking exclusively about pedestrian bridges. If we recall Soviet times, then one-off examples will be structures in the Ruza district of the Moscow region (1966) and in Leningrad (1969). In a planned economy, this can be attributed to ineffective resource management. However, even now bridges continue to be built from reinforced concrete and steel.
Unfortunately, in Russia time is rarely taken into account as a resource. And the use of aluminum structures allows you to save money both during installation and when transporting them to the construction site. The time required for traffic restrictions associated with the installation of aluminum spans on supporting parts is also reduced. For example, the already mentioned pedestrian bridges in the Nizhny Novgorod region were installed in just two hours. When using reinforced concrete or steel, one cannot help but dream of such indicators. The weight of an aluminum bridge deck with the same load capacity is 5-6 times less than the weight of reinforced concrete (80–120 kg per square meter for aluminum alloys versus 500 kg per square meter for reinforced concrete) and 2-4 times less than the weight of steel. This means that when reconstructing bridge structures, the throughput can be increased while leaving the design of the supports unchanged. When constructing a new bridge, by reducing the weight of the structure, the cost of their construction is reduced.
This is not the end of the economic effect. High resistance to corrosion, low temperatures, high humidity and moderately aggressive environments not only ensures a long service life, but also allows the use of aluminum in bridge construction in almost any conditions. Moreover, the strength of aluminum increases with decreasing temperature, which eliminates the need for regular inspections of structures under operating conditions at temperatures below minus 35 degrees Celsius. For Russia, where in many regions the temperature remains at sub-zero levels for most of the year, this is very important.
Everything is so logical, but how can we explain the habit of building with steel and concrete? While many countries that we look up to actively use aluminum in road infrastructure, we are still in the twentieth century, because the first aluminum bridge span appeared in the USA in 1946, and a few years later in Europe.
There is another obstacle in Russia: the lack of domestic regulatory and technical documentation necessary for effective and full-scale design. In accordance with current legislation, for each project of a new bridge made of aluminum alloys, the development of special technical conditions is currently required. In addition, there is a lack of knowledge among designers and planners about new materials for bridge construction, which is why preference is given to less effective, but familiar alternatives. In this case, it is impossible to do without introducing the best foreign practices.
To walk the road to the future, you cannot stand still. The shortest path is always a straight line, which means we need to build bridges rather than look for workarounds.
